Wood burning stove - conflicting information

Yorky

Hello all,

I'm looking to install two wood burning stoves but am literally bamboozled by conflicting information.

Specifically, whether to line a 8"/200mm flue or not and whether to fit a boiler (wet) stove or not.

The conflicting information is:

The flue definitely does/doesn't need to be lined
Do / do not fit a boiler stove.

Would appreciate any insight in to this.

Thanks in advance

bbam

I have a stove with 100K btu boiler heating rads... Great job and it heats a 28*14 room no bother too..

My understanding is that technically yes the flue needs to be lined, ours isn't.

paddy147

I was advized by 2 diferent fireplace shops to get a twin walled stainless steel flexi flue liner installed for my Stovax Stove.

It helps with the performance of the stove and the draw of it

You match the liner to the outlet size of the stove.

In my case 6 inch liner for a 6 inch outlet,for best performance and draw.

Yorky

bbam wrote: »

I have a stove with 100K btu boiler heating rads... Great job and it heats a 28*14 room no bother too..

Thanks for the reply. Which make/model is it & how many rads do you have? Also have you any photos which could be viewed?

paddy147 wrote: »

I was advized by 2 diferent fireplace shops to get a twin walled stainless steel flexi flue liner installed for my Stovax Stove.

It helps with the performance of the stove and the draw of it

You match the liner to the outlet size of the stove.

In my case 6 inch liner for a 6 inch outlet,for best performance and draw.

Thanks for the reply. Do you have an 8" flue? Also, the make / model & is it a boiler stove?

PeteHeat

The flue should be lined and back filled with vermiculite for the reasons mentioned by paddy147

The insulated flue liner also prevents a build up of condensate (creosote) in the flue which can be very dangerous in the event of a chimney fire, also it is almost impossible to clean the chimney properly if you have to run the brushes through a 5 / 6" stove spigot and hope the brushes are strong enough to clean the 8" clay flue liner.

As to the stove with a boiler it is important to ensure you have a supply of cheap fuel such as trees around your own property because buying solid fuel can be expensive.

Also check the true cost of installing a solid fuel appliance to your existing heating system, if you have a fairly new heating system it is most likely a pressurised or sealed system, solid fuel stoves must only be installed to an open vent system, it is possible to modify most pressurised systems to open vent however it can have its draw backs.

I hope the above is of some help.
.

paddy147

Yorky wrote: »

Thanks for the reply. Which make/model is it & how many rads do you have? Also have you any photos which could be viewed?




Thanks for the reply. Do you have an 8" flue? Also, the make / model & is it a boiler stove?

Mid 1950s house with an 8 inch diameter flue/chimney.

Stovax Riva 66 8kw stove.

No boiler in it.

Its a multi fuel insert stove and it chucks out some serious heat.

Yorky

Thanks. Where's the best place to get the flue liner & kit from?

bbam

Yorky wrote: »

Thanks for the reply. Which make/model is it & how many rads do you have? Also have you any photos which could be viewed?

Hercules 30B, made by Brosley


Not sure about how many rads you'd count, remember official numbers of rads are based on 5ft or 6ft singles..

We have somewhere in the region of 20 doubles, ranging from 3ft to 5ft and two towel rails... They wouldn't all be on at any one time.. Typically it would be heating about 10-12 doubles very well.. With TRV's and thermostatic zoning etc its hard to say which are "on" at any one time.

One shot on kill

You most definitely need a steel flue because the clay flues will keep poping with the heat ( they don't make them as good anymore ).

I'm in the process of doing my chimney at the minute and I was and advised not to pull down a flue but completely reline with a steel flue because when you pull a flexy flue down it increases your chances of a chimney fire if it's touching the clay flue liners. I know you fill with the vermicalite but how can you be sure it's completely surrounded.

If I were you I would get action chimneys to do a survey on your chimney and they will advise you the best coarse of action. And it only costs 50 euro. And they are very good. Infairness.

seoirse1980

I'm not sure about the advice you have been given.

One shot on kill wrote: »

You most definitely need a steel flue because the clay flues will keep poping with the heat ( they don't make them as good anymore ).

I'm in the process of doing my chimney at the minute and I was and advised not to pull down a flue but completely reline with a steel flue because when you pull a flexy flue down it increases your chances of a chimney fire if it's touching the clay flue liners. I know you fill with the vermicalite but how can you be sure it's completely surrounded.

If I were you I would get action chimneys to do a survey on your chimney and they will advise you the best coarse of action. And it only costs 50 euro. And they are very good. Infairness.

If the advice is for the flue for a wood burning stove. A clay liner will not 'pop' with the heat and possibly be better if one incorrectly slumbers the appliance for long periods, particularly using solid mineral fuel,combined with inadequate cleaning of flueways. These bad habbits could reduce a flexi liners life to 5 years.

However when looking to reline a flue for an efficient wood stove a stainless steel flue in 316 would be the recommended minimum. Even better would be a 904 grade of liner as this is suitable for multi fuel burning and provided the above conditions are not occurring.

This liner can then be backfilled with vermiculite or similar or if you were worried that the insulation could not surround it, a wrap of special insulation could then be used before installation.

Soot and creosote will increase the chances of a chimney fire not the fact that a flexi is touching a clay liner. as long as the chimney has been cleaned before fitting of the stainless liner. A clean chimney should not go on fire.

This can be helped by fitting an appropriately sized flexible flue, this will ensure that the velocity of the flue gases will not decrease as they travel into a larger flueway. This can further be helped by backfiling the flue with an insulating material so not to give the flue gases a chance to cool,reach dew point, leave condensates on the inside of the flue.

By all means get the chimney looked at by a professional chimney sweep if you are not confident in your knowledge or experience.

Hope this helped,

George

'The soot doctor'